Adaptors for connecting computer modems, and other electrical equipment having RJ-11 type sockets, to telephone systems that utilize plugs/sockets other than the RJ-11 type are well known in the art cs illustrated in Magellan's Summer/Fall 1997 Catalog, USA; Toshiba 1997 Winter Accessories Catalog, USA; and TeleAdapt Limited UK Catalog. Moreover, electrical connectors for adapting electrical equipment having an RJ-11 type socket to a different type of electrical plug/socket are also known as shown in U.S. Pat. No. 4,362,905 to Ismail and U.S. Pat. No. 4,740,172 to Tubbs.
A problem with such adaptors, however, is that they only enable connection between plugs/sockets of two different telephone systems. Hence, a traveler visiting a plurality of different countries with, for example, a computer modem having an RJ-11 plug, would require a suitable plug/socket interface arrangement for each country that utilized a different standard plug/socket for its national telephone equipment. This is a problem because of the cost and inconvenience associated with purchasing a plurality of different pluglsocket interface arrangements, one for each country; the need to identify which plug/socket arrangement is utilized in each country; and
the need to carry a plurality of plug/socket arrangements while traveling. Still another problem arises in having a traveler, who is potentially unfamiliar with telephone wiring, construct a plug/socket interface arrangement between different telephone systems.
It is therefore an object of the present invention to overcome the above problems and others by providing a telephone adaptor that enables connection between an RJ-11 socket and plugs/socket of a plurality of different telephone systems. It is a further object of the present invention to provide a telephone adaptor that includes protection circuitry to protect electrical equipment connected to the RJ-11 socket from line surges and voltage spikes. Finally, it is an object of the invention to provide a telephone adaptor that includes circuitry for detecting non-standard telephone line voltages and for providing an indication thereof.